Personal care device

ABSTRACT

A personal care device having a handle having an engagement portion and a persona care attachment are described. The personal care attachment has a housing attached to the engagement portion and a contact element carrier. The contact element carrier is movably coupled to the housing. A plurality of contact elements is arranged on the contact element carrier, and wherein the personal care attachment is driven at a frequency of between about 150 Hz to about 175 Hz and has a sound intensity level of less than about 75 dB(A).

FIELD OF THE INVENTION

The present invention pertains to powered personal care devices, andmore particularly to powered oral care devices.

BACKGROUND OF THE INVENTION

The utilization of toothbrushes to clean one's teeth has long beenknown. There are generally two types of toothbrushes currently availableon the market, e.g. manual and power. In general, for manual brushes, auser provides the majority of the cleaning motion to the brush in theoral cavity. In contrast, for power brushes, a motor providing a drivingforce to all or a portion of a head of the toothbrush provides themajority of the cleaning motion to the brush which cleans the oralcavity.

The powered toothbrush typically includes a handle having a motor andpower supply therein. In general, the motors supply rotational orlongitudinal energy to the refill which is attached to the handle.Normal operating speeds for powered toothbrushes can vary. For example,toothbrushes having oscillating/rotating heads, typically operate in therange of 40 Hz to 100 Hz. In contrast, some toothbrushes available onthe market are termed “sonic” and can operate in the range of 160 Hz to300 Hz. However, sonic toothbrushes do not include oscillating/rotatingmotion.

The drive train of the oscillating/rotating toothbrushes typicallyincludes gearing which modifies the rotational energy of the motor. Forexample, many oscillating/rotating toothbrushes include a drive trainwhich converts the 360 degress motion of a motor output shaft to asmaller oscillating angle of displacement on drive shaft. A refillcouples to the drive shaft and typically modifies the direction of therotational energy of the drive shaft. Because of these conversions ofangle, displacement and/or direction, increased frequency in currentlyavailable oscillating/rotating brushes may not be realizable.

Oscillating/rotating toothbrushes with a round or oval shaped brushheadhave been proven to be more efficient for the cleaning of teeth thanother systems. It is believed that higher drive frequencies have thepotential to further improve the mechanical cleaning offered byoscillating/rotating toothbrushes and to generate fluid dynamics effectsduring brushing which is believed to contribute to the cleaning.However, due to the gear systems included in the conventionaloscillating/rotating toothbrushes operation at higher frequencies islimited because of the associated noise. Accordingly, conventionaloscillating/rotating toothbrushes operate in the frequencies describedabove.

As such, there is a need for an oscillating/rotating toothbrush whichcan operate at frequencies greater than 100 Hz.

SUMMARY OF THE INVENTION

Embodiments of the present invention can provide a user with a personalcare device which has reduced sound intensity levels. In the embodimentswhere the personal care device comprises a toothbrush, anoscillating/rotating toothbrush can provide the user with bettercleaning and lower noise than conventional oscillating/rotating brushes.

In some embodiments, a personal care device comprises a handle having anengagement portion, and a personal care attachment. The personal careattachment comprises a housing attached to the engagement portion and acontact element carrier. The contact element carrier is movably coupledto the housing. A plurality of contact elements is arranged on thecontact element carrier, wherein the personal care attachment is drivenat a frequency of between about 150 Hz to about 175 Hz and has a soundintensity level of less than about 75 dB(A).

In some embodiments, a personal care attachment comprises a housing; acontact element carrier movably mounted to the housing; and a drivemember disposed within the housing. The drive member has a proximal endand a distal end. The proximal end has an attachment element and thedistal end comprises a connection coupled to the contact elementcarrier. The attachment element comprise a permanent magnet or amagnetisable material.

In some embodiments, a personal care attachment comprises a housing; acontact element carrier movably mounted to the housing; and a drivemember disposed within the housing. The drive member has a proximal endand a distal end. The proximal end has an attachment element and thedistal end comprises a connection coupled to the contact elementcarrier. The connection is positioned at an angle of less than about 40degrees with respect to a horizontal plane.

BRIEF DESCRIPTION OF THE DRAWINGS

It is to be understood that both the foregoing general description andthe following detailed description describe various embodiments and areintended to provide an overview or framework for understanding thenature and character of the claimed subject matter. The accompanyingdrawings are included to provide a further understanding of the variousembodiments, and are incorporated into and constitute a part of thisspecification. The embodiments set forth in the drawings areillustrative in nature and not intended to be limiting of the subjectmatter defined by the claims. The drawings illustrate variousembodiments described herein, and together with the description serve toexplain the principles and operations of the claimed subject matter.

FIG. 1A is a perspective view showing a toothbrush constructed inaccordance with an embodiment.

FIG. 1B is a perspective view showing a handle of the toothbrush of FIG.1A.

FIG. 1C is a cross section taken along a longitudinal axis showing arefill of the toothbrush of FIG. 1A.

FIG. 2 is a close up view showing a front face of a contact carrierelement of the refill of FIG. 1C.

FIG. 3 is a close up view showing the front face of the contact carrierelement of the refill of FIG. 1C and an oscillation displacement angle.

FIG. 4 is a close up view showing a front face of a contact carrierelement another embodiment of a refill.

FIG. 5 is a graph showing the oscillation displacement angle for aplurality of refills under varying loads and under no load.

FIG. 6 is a lateral cross section showing the refill of FIG. 1C.

FIG. 7 is a lateral cross section showing an embodiment of a handle.

FIG. 8 is a longitudinal cross section showing an interconnectionbetween the refill fo FIG. 6 and the handle of FIG. 7.

FIG. 9 is a close up view of a partial cross section showing anembodiment of a refill.

FIG. 10 is a close up view of a lateral cross section showing anotherembodiment of a refill.

FIG. 11A is an elevation view of a test set up to measure oscillationdisplacement angle.

FIG. 11B is a circuit diagram showing a plurality of photodiodes andtheir arrangement for the sensor arrays in the test set up of FIG. 11A.

FIG. 11C is a plan view showing a portion of the test set up of FIG.11A.

FIG. 12 is an elevation view showing a test stand for supporting handheld devices for sound intensity testing.

FIG. 13 is a schematic representation showing wireless communicationbetween/among a personal care device and a display.

FIG. 14 is a cross section showing another embodiment of a linear motorfor use in an embodiment of a personal care device.

DETAILED DESCRIPTION OF THE INVENTION

The following text sets forth a broad description of numerous differentembodiments of the present invention. The description is to be construedas exemplary only and does not describe every possible embodiment sincedescribing every possible embodiment would be impractical, if notimpossible, and it will be understood that any feature, characteristic,component, composition, ingredient, product, step or methodologydescribed herein can be deleted, combined with or substituted for, inwhole or part, any other feature, characteristic, component,composition, ingredient, product, step or methodology described herein.Numerous alternative embodiments could be implemented, using eithercurrent technology or technology developed after the filing date of thispatent, which would still fall within the scope of the claims. Allpublications and patents cited herein are incorporated herein byreference.

It should also be understood that, unless a term is expressly defined inthis patent using the sentence “As used herein, the term ‘______’ ishereby defined to mean . . . ” or a similar sentence, there is no intentto limit the meaning of that term, either expressly or by implication,beyond its plain or ordinary meaning, and such term should not beinterpreted to be limited in scope based on any statement made in anysection of this patent (other than the language of the claims). No termis intended to be essential to the present invention unless so stated.To the extent that any term recited in the claims at the end of thispatent is referred to in this patent in a manner consistent with asingle meaning, that is done for sake of clarity only so as to notconfuse the reader, and it is not intended that such claim term belimited, by implication or otherwise, to that single meaning. Finally,unless a claim element is defined by reciting the word “means” and afunction without the recital of any structure, it is not intended thatthe scope of any claim element be interpreted based on the applicationof 35 U.S.C. §112, sixth paragraph.

The personal care devices of the present invention can operate at afrequency of greater than 100 Hz. The personal care devices of thepresent invention may comprise shavers, razors, flossers, irrigators,etc., however, for convenience, the description below focuses primarilyon toothbrushes.

Referring to FIGS. 1A and 1C, in one embodiment a toothbrush 10comprises a handle 12 and a personal care attachment, e.g. refill 21.The refill 21 may be removably attached to the handle 12. The handle 12comprises an engagement portion 14 at a distal end 75 of the handle. Thehandle further includes a proximal end 80, longitudinal axis 99, and adrive shaft 35.

The drive shaft 35, when in operation, may be driven in a directionwhich is substantially parallel to the longitudinal axis 99.Additionally, a drive system (discussed hereafter) within the handle 12may comprise a linear motor. In some embodiments, the drive system maynot comprise gearing between the linear motor and drive shaft. In someembodiments, discussed hereafter, a drive shaft may be provided withoscillating/rotating motion.

The refill 21 comprises a housing 20 and contact element carrier 22 thatis rotatably coupled to the housing 20. A plurality of contact elements24 are attached to the contact element carrier 22. The refill 21comprises a longitudinal axis 100 which can, in some embodiments, beco-linear with the longitudinal axis 99 of the handle 12 when thehousing 20 engages the engagement portion 14. The contact elementcarrier 22 oscillates about a rotational axis 95 such that the contactelement carrier 22 rotates back and forth as shown by double arrow 97.

As shown in FIG. 2, the contact element carrier 22 comprises an innerregion 210 and a peripheral region 220. The peripheral region 220 isdisposed adjacent a periphery 222 of the contact element carrier 22. Theinner region 210 is disposed inboard of the peripheral region 220, i.e.nearer the rotational axis 95 (shown in FIG. 1C).

The contact elements 24 may be disposed in openings 240 in the contactelement carrier 22. The portion of the contact element 24 disposed inthe opening 240 is the attached end. The contact elements 24 extend to atip end opposite the attached end. The contact elements 24 may beattached to the cleaning element carrier 22 by any suitable means. Forexample, stapling or anchoring may be utilized. As yet another example,the contact elements 24 may be attached to the contact element carrier22 via anchorless technologies, e.g. in mold tufting (IMT), anchor freetufting (AFT), the like, or combinations thereof Additionally,embodiments are contemplated where combinations of anchor free andanchor tufting may be utilized. Additional attachment methods may beavailable depending on the type of contact element utilized. Suchadditional attachment methods are discussed hereafter.

Referring to FIGS. 1C and 2, the contact elements 24 comprise a firstplurality of contact elements 33 arranged on the contact element carrier22 in the inner region 210, and a second plurality of contact elements31 arranged on the contact element carrier 22 in the outer region 220.

As stated previously, the contact elements 24 comprise an attached endand a tip end. In some embodiments, the tip ends of the second pluralityof contact elements 31 are driven such that at least a portion of, ifnot all of the second plurality of contact elements 31 have a tip speedof about 1.5 m/s or greater. It is believed that with tip speeds ofabout 1.5 m/s or greater, liquid flows in the oral cavity may begenerated which contribute to the cleaning of oral surfaces.

The tip speeds of the contact elements 24 are determined by thefollowing equation:

V=2πfA

where f=frequency of oscillation and A=amplitude. The amplitude iscalculated based, in part, upon an oscillation displacement angle. Asshown in FIGS. 2 and 3, the oscillation displacement angle 310 isdefined by the movement of point 315 on the periphery 222 of the contactelement carrier 22. With respect to the rotational axis 95 (shown inFIG. 1C) point 315 may rotate in a first direction at a first angle 305and in a second direction at a second angle 303 during operation. Thefirst angle 305 and the second angle 303 cumulatively form thedisplacement angle 310. The amplitude is then determined by thefollowing equation:

$A = \frac{{\alpha\pi}\; r}{180}$

where α=the displacement angle 310 and r is the distance from therotational axis 95 (shown in FIG. 1C) to a center point of the opening240 (shown in FIG. 2) in which the contact element for which the tipspeed is being determined is disposed. It is worth noting that in someembodiments, the radius of the contact element carrier is usuallymeasured in millimeters where the velocity (tip speed) being determinedis in meters. So, some additional calculations may be required toconvert the units for the amplitude and/or the velocity to ensure thatm/s is derived in the tip speed equation.

Additionally, because amplitude is based, in part, upon the radius thatthe contact element is away from the rotational axis 95 (shown in FIG.1C), the first plurality of contact elements 33 should have lower tipspeeds than those of the second plurality of contact elements 31. Insome embodiments, the first plurality of contact elements 33 or aportion thereof are driven such that they have a tip speed of at least1.5 m/s.

Generally, manufacturers try to utilize as much surface area of thecontact element carrier as possible. As such, for larger diametercontact element carriers, a larger radius between the rotational axisand the outermost contact elements may be realized which can facilitatereaching the goal of 1.5 m/s at lower frequencies. However, the diameterof contact element carriers is constrained because of mouth feel, e.g.user perception. In general, larger diameter contact element carriersmay be perceived as uncomfortable or too large to provide cleaning to anadequate number of teeth particularly those in the back of the oralcavity. For example, a contact element carrier having a large diameter,e.g. above 14 mm, may cause some discomfort to the user or seem bulkyduring use.

As such, the diameter of the contact element carrier 22, in someembodiments, is between about 8 mm to about 16 mm. The diameter of thecontact element carrier 22 may be greater than about 8 mm, greater thanabout 9 mm, greater than about 10 mm, greater than about 11 mm, greaterthan about 12 mm, greater than about 13 mm, greater than about 14 mm,greater than about 15 mm, greater than about 16 mm, greater, or lessthan about 16 mm, less than about 15 mm, less than or equal to about 14mm, less than about 13 mm, less than about 12 mm, less than about 11 mm,less than about 10 mm, or any number or any ranges including or withinthe values provided.

Referring to FIG. 4, in order to achieve greater coverage, i.e. contactelement area, embodiments are contemplated where a contact elementcarrier 422 comprises a non-circular surface. For example, the contactelement carrier 422 may comprise an oval or elliptical shape having amajor axis 433 and a minor axis 431. As shown, the major axis 433 may begenerally aligned with a longitudinal axis 400 of refill 401, in someembodiments. However, in some embodiments, the major axis 433 may beoffset from the longitudinal axis 400 of the refill 401.

In some embodiments, a diameter along the minor axis 431 is betweenabout 8 mm to about 16 mm as described above with regard to the diameterof the contact element carrier 22 and may be any number or rangedescribed heretofore with regard to the cleaning element carrier 22(shown in FIG. 3). In some embodiments, a diameter along the major axis433 is between about 9 mm to about 19 mm. The major axis 433 may begreater than about 9 mm, greater than about 10 mm, greater than about 11mm, greater than about 12 mm, greater than about 13 mm, greater thanabout 14 mm, greater than about 15 mm, greater than about 16 mm, greaterthan about 17 mm, greater than about 18 mm, greater than about 19 mm, orless than or equal to about 19 mm, less than about 18 mm, less thanabout 17 mm, less than about 16 mm, less than about 15 mm, less thanabout 14 mm, less than about 13 mm, less than about 12 mm, less thanabout 11 mm, less than about 10 mm, or any number within or any rangewithin or including the values above. In such embodiments, the radius ismeasured in the same way as described heretofore, i.e. distance from arotational axis 495 to a center point of the contact element or to thecenter point of the opening in in which the desired contact elementresides. The equations provided above may be applied to contact elementcarriers having an oval or elliptical surface.

For those embodiments where the contact element carrier 422 comprises anoval or elliptical shape, a second plurality of contact elements 441 maybe disposed on opposite sides of the contact element carrier 422adjacent the major axis 433. In some embodiments, the contact elementcarrier 422 is driven at a frequency and/or amplitude such that thesecond plurality of contact elements 441 have a tip speed of at least1.5 m/s. Additionally, in some embodiments, the contact element carrier422 is driven at a frequency and/or amplitude such that a firstplurality of contact elements 443 adjacent the minor axis 431 have a tipspeed of at least 1.5 m/s. In other embodiments, the contact elementcarrier 422 may be driven at a frequency and/or amplitude such that thesecond plurality of contact elements 441 have a tip speed of at least1.5 m/s while the first plurality of contact elements 443 have a tipspeed of less than 1.5 m/s.

Many tip speeds may be utilized for the contact elements. For example,the second plurality of contact elements may have a tip speed of atleast 2.5 m/s. In some embodiments, the tip speed of a portion of thecontact elements may be greater than about 1.3 m/s, greater than about1.4 m/s, greater than about 1.5 m/s, greater than about 1.6 m/s, greaterthan about 1.7 m/s, greater than about 1.8 m/s, greater than about 1.9m/s, greater than about 2.0 m/s, greater than about 2.1 m/s, greaterthan about 2.2 m/s, greater than about 2.3 m/s, greater than about 2.4m/s, greater than about 2.5 m/s, or less than about 2.5 m/s, less thanabout 2.4 m/s less than about 2.3 m/s, less than about 2.2 m/s, lessthan about 2.1 m/s, less than about 2.0 m/s, less than about 1.9 m/s,less than about 1.8 m/s, less than about 1.7 m/s, less than about 1.6m/s, less than about 1.5 m/s, or any number or any range within orincluding these values.

As shown in the above equations, a tip speed of 1.5 m/s can be achievedvia a larger radius, i.e. distance from the rotational axis to thecontact element for which the velocity is being determined. However, asdiscussed previously, the size of the contact element carrier may beconstrained because of mouth feel during use. Additionally, the tipspeed of 1.5 m/s can be achieved via the amplitude of the contactelement carrier 22, 422. However, as above, the amplitude may beconstrained by a user based upon mouth feel. For example, a largeoscillation displacement angle, which impacts amplitude, can cause theuser to feel that the brush is too aggressive. In contrast, too low ofan oscillation displacement angle can cause inhibit the cleaning effectof the toothbrush, but also may impact the frequency of operation suchthat too high of an operating frequency is required to achieve a 1.5 m/stip speed.

Additionally, a larger amplitude may be difficult to achieve because ofcost considerations. For example, for larger amplitudes ball bearings orsprings may be required which can increase the cost and complexity ofthe refill.

In some embodiments, the oscillation displacement angle 310 (shown inFIG. 3) is greater than about 5 degrees to about 60 degrees. Theoscillation displacement angle 310 (shown in FIG. 3) may be greater thanabout 5 degrees, greater than about 10 degrees, greater than about 15degrees, greater than about 20 degrees, greater than about 25 degrees,greater than about 30 degrees, greater than about 35 degrees, greaterthan about 40 degrees, greater than about 45 degrees, greater than about50 degrees, greater than about 55 degrees, greater than about 60degrees, or less than about 60 degrees, less than about 55 degrees, lessthan about 50 degrees, less than about 45 degrees, less than about 40degrees, less than about 35 degrees, less than about 30 degrees, lessthan about 25 degrees, less than about 20 degrees, less than about 15degrees, less than about 10 degrees, or any number or any range withinor including the values provided.

Also as shown by the previous equations, the frequency of operation alsoimpacts tip speed. Similar constraints may be present with regard tooperating frequency. For example, an operating frequency which is toolow may make a user feel like the device is not operating properly ornot performing as well as it should. In contrast, too high of anoperating frequency may cause the user to feel that the device is tooaggressive. Additionally, to high of an operating frequency may producehigher noise levels which can irritate the user. These higher noiselevels may be particularly relevant where the drive frequency and theresonance frequency of the personal care device or the resonance of thepersonal care attachment, e.g. refill 21, 401, are close together. Thediscussion of resonance frequency and noise levels is providedhereafter.

In contrast, in some embodiments, the toothbrushes may utilize a desiredoperating frequency and/or a desired oscillation displacement angle inorder to achieve a tip speed of at least 1.5 m/s, while alsoemitting/producing reduced noise levels during operation. The noiselevels of the toothbrushes constructed in accordance with the inventionare discussed hereafter.

Additionally, a user's perception of a specific movement can be varieddepending on the frequency of the movement. For example, a specificmovement at a frequency below 120 Hz may be very perceptible to a userwhereas the same movement at a frequency of greater than about 120 Hz isless perceptible. In some embodiments, the operating frequency isgreater than about 120 Hz. The operating frequency can be greater thanabout 120 Hz, greater than about 130 Hz, greater than about 140 Hz,greater than about 150 Hz, greater than about 160 Hz, greater than about170 Hz, greater than about 180 Hz, greater than about 190 Hz, greaterthan about 200 Hz, or less than about 200 Hz, less than about 190 Hz,less than about 180 Hz, less than about 170 Hz, less than about 160 Hz,less than about 150 Hz, less than about 140 Hz, less than about 130 Hz,and/or any number or any range within or including these values.

Conventional brushes often can provide operating frequencies of lessthan 100 Hz and/or oscillation displacement angles of about 20 degreesin no load conditions; however, in the loaded state, often timesoscillation displacement angle and/or frequency can drop significantly.With some conventional toothbrushes, an applied load to the contactelement field causes a decrease in the frequency; however, due to thegearing in the handle and/or refill, the oscillation displacement angleremains constant.

Motor Control

Because the cleaning fluid flows described above occur within the oralcavity when contact elements have tip speeds of at least 1.5 m/s, insome embodiments, the amplitude and/or frequency may be kept at adesired level in both load and no load conditions in order to achievethe 1.5 m/s tip speed for at least a portion of the contact elements.For example, in some embodiments, the toothbrushes may comprise a loaddetector which can determine the load applied to the toothbrush duringbrushing. The load detector can be in signal communication with acontroller.

In some embodiments, a toothbrush may comprise a detector which measuresan operating parameter of a motor and detects changes therein. Theoperating parameter may comprise at least one of speed, amplitude,operating frequency, the like, or combinations thereof Additionally, insome embodiments, a characteristic electrical parameter may be measuredin addition to or indepently of the operating parameters mentionedpreviously. In such embodiments, the characteristic electricalparameters may include current consumption. Additional embodiments arecontemplated where load is determined based upon input from the motor.Such embodiments are discussed in applications filed in the EuropeanPatent Office (“EPO”) entitled “PERSONAL CARE DEVICE”, filed on Jul. 25,2011, having an attorney docket number of Z-08588FQ and in anapplication filed in the EPO entitled “RESONANT MOTOR UNIT AND ELECTRICDEVICE WITH RESONANT MOTOR UNIT”, filed on Jul. 25, 2011, and having anattorney docket number Z-08572FQ.

Regardless of how loaded versus an unloaded state are determined for thetoothbrush, when in a loaded state, i.e. during brushing, the controllermay adjust the pulse width modulation (PWM) of the power supplied to amotor in an effort to keep the oscillation displacement at a desiredlevel such that the tip speed of at least 1.5 m/s is achieved on atleast a portion of the contact elements. For example, in order to modifythe oscillation displacement angle, the width of the pulses provided tothe motor may be increased thereby supplying more power per pulse. Assuch, an increase in the pulse width may result in greater oscillationdisplacement angle. In order to modify the frequency, the centerlinespacing between pulses can be varied. For example, increased centerlinespacing between pulses results in a lower frequency while decreasedcenterline spacing between pulses results in increased frequency.Adjustment of the PWM will be considered to include the modification ofwidth of an individual pulse or a plurality of pulses and/ormodification to the centerline spacing between adjacent pulses. For thepersonal care devices of the embodiments described, an applied load onlyimpacts amplitude and not frequency.

As stated previously, in at least one operational mode, a contactelement carrier may be driven such that a plurality of contact elementshave a tip speed of at least 1.5 m/s. A desired range of frequencies(discussed heretofore as the operating frequency) and/or desired rangeof oscillation displacement angles (discussed heretofore as oscillationdisplacement angle) may be utilized to accomplish this tip speed. Insome embodiments, the toothbrushes can maintain an operating frequencywithin the desired range of frequencies and/or an operating oscillationdisplacement angle within the desired range of oscillation displacementangles even with loads of greater than zero newtons, e.g. about 2 N toabout 3 N, applied to the contact element field. For example, when aload above zero N is detected, the PWM may be modified such that thedrive system maintains an oscillation displacement angle which is withinthe desired oscillation displacement angle range. As another example,under no load, a first operating oscillation displacement angle may berealized. Under a load of about greater than zero newtons to about 3 N,a second operating oscillation displacement angle may be realized, wherethe second operating oscillation displacement angle is at least about 74percent of the first operating oscillation displacement angle. In someembodiments, the contact element carrier may have a second operatingoscillation displacement angle which is at least about 74 percent of thefirst oscillation displacement angle, at least about 75 percent, atleast about 80 percent, at least about 85 percent, at least about 90percent, at least about 95 percent, at least about 98 percent, at leastabout 99 percent, at least about 100 percent, and/or any number or anyranges within or including the values above.

Oscillation displacement angles impact the amplitude. As such, theoscillation displacement angle under no load may be about 40 degrees andthe oscillation displacement angle under load is about 30 degrees. Insome embodiments, under a load of about 1 N to about 3N, the oscillationdisplacement angle may be about 10 degrees. Oscillation displacementangles under no load and under load are shown in FIG. 5 for prototypesof toothbrushes constructed in accordance with the present invention.

As shown in FIG. 5, some prototypes were tested under no load and undervarious applied loads. Some of the prototypes were tested at multiplefrequencies. For each of the prototypes tested, at no load, theoscillation displacement angle was about 40 degrees. Under a 1 N load,the oscillation displacement angle for each prototype dropped toslightly below 40. Even at a loading of about 3 N, the prototypesprovided an oscillation displacement angle of between about 25 degreesand about 30 degrees. Accordingly, if at a load of 3 N, the tip speed ofat least a portion of the contact elements is at least 1.5 m/s, thenbecause of the higher oscillation displacement angles at a load of 1N,assuming the same operating frequency at 1 N and at 3 N, the tip speedof the at least a portion of contact elements would be greater than 1.5m/s. In such instances, the PWM may be adjusted down for the lighterload such that either the oscillation displacement angle and/or thefrequency are reduced such that the at least a portion of contactelements are have tip speeds of about 1.5 m/s.

Another problem with conventional toothbrushes is that generally wheninitially powered on, the toothbrush operates at full speed, e.g.maximum frequency and/or maximum amplitude. For example, a conventionaltoothbrush having an operating frequency under no load of 75 Hz and adisplacement angle of 20 degrees under no load will generally operate atthat frequency and displacement angle the instant that the toothbrush isturned on. However, this can be problematic in that if a user appliestoothpaste to the contact element field, the frequency and displacementangle of the toothbrush will tend to fling the toothpaste off of thecontact elements. Additionally, when a user is done brushing, theremoval of the toothbrush from the oral cavity, in the powered on state,can cause similar problems, i.e. flinging of used toothpaste off of thecontact element field.

As such, in some embodiments, toothbrushes may comprise a controllerwhich provides an idle run state for a no load condition and a normalrun state for a loaded condition, wherein the idle run state and thenormal run state are different. For example, during the normal runstate, i.e. during brushing, the controller may adjust the PWM such thatthe tip speed of the second plurality of contact elements is at least1.5 m/s. In contrast, during the idle run state, e.g. outside of theoral cavity under no load, the controller may adjust the PWM such thatthe tip speed of the second plurality of contact elements is less than1.5 m/s. In some embodiments, the adjustment of the PWM may impact theoperating frequency and/or the oscillation displacement angle whichimpacts amplitude.

In such embodiments, the controller may be configured such that if aload of about zero newtons is detected, the idle run state, e.g. noload, is implemented. The idle run state may be selected automaticallyby the controller when the toothbrush is initially powered on.Additionally, after a brushing for a predetermined time period, e.g. twominutes, three minutes, the controller may initiate the idle run statesuch that the user removing the toothbrush from his/her mouth does notfling used toothpaste from the contact element field. Additionally, theinitiation of the idle run state after the predetermined time can signalthe user that he/she has brushed for a sufficient amount of time.

If a load above or equal to about zero newtons is detected, then anormal run state may be implemented. In the normal run state, thecontroller may adjust the PWM to ensure that the second plurality ofcontact elements have a tip speed of at least 1.5 m/s. If a load ofabout 3 N is detected, then a third run state may be implemented. In thethird run state, the controller may again, adjust the PWM therebyincreasing the power supplied to the drive system. The adjustment of thePWM in the third run state would be to ensure that the second pluralityof contact elements maintain a tip speed of at least 1.5 m/s even underan increased load.

In some embodiments, if a load above or equal to about 3 N is detected,then the PWM may be adjusted such that damage to the teeth and/or gumsof a user is reduced or precluded altogether. For example, for anexerted force that could cause harm to the teeth and/or gums to theuser, the controller may adjust the PWM such that the amplitude and/orfrequency are reduced.

In the idle run state under no load and/or in the after brushing statedescribed above, the PWM may be adjusted such that the amplitude isreduced from that of the norlam run state. For example, the amplitudemay be reduced be less than or equal to about 30 percent, less thanabout 25 percent, less than about 20 percent, less than about 15percent, less than about 10 percent, or any number or any range withinor including the values provided.

Similarly, in the idle run state under no load and/or in the afterbrushing state described above, the PWM may be adjusted such that thereis a decrease in frequency from that of the normal run state. Forexample, the frequency may be reduced by less than or equal to about 30percent, less than about 25 percent, less than about 20 percent, lessthan about 15 percent, less than about 10 percent, or any number or anyrange within or including the values provided.

In some embodiments, the toothbrushes can offer the user with a largeamount of flexibility. In addition to the idle run state and the normalrun state, many other additional operating options may exist. Forexample, as stated previously, adjustment of the PWM can impact theamplitude as well as the frequency. As such, a controller, in someembodiments, can provide the user with a plurality of operating modeswhich modify either the amplitude and/or the frequency. In contrast,conventional toothbrushes have gearing within the handle and/or therefill which fixes the oscillation displacement angle regardless of thevoltage applied to the motor. As such, adjustments to the PWM of aconventional toothbrush results only in changes to the operatingfrequency.

With regard to the variation in amplitude, any increase or decrease maybe realized by modifying the oscillation displacement angle. As suchhereafter, an increase in amplitude can mean an increase in oscillationdisplacement angle while a decrease in amplitude can mean a decrease inoscillation displacement angle.

In some embodiments, a controller may allow the user to select anoperation mode in which the amplitude is increased by up to about 25%for a predetermined period of time. For convenience, the AI (amplitudeincrease) mode. The increase in amplitude may be any suitable percentageof the desired amplitude (discussed heretofore). For example, theincrease in amplitude may be greater than about 5 percent, greater thanabout 10 percent, greater than about 15 percent, greater than about 20percent, greater than about 25 percent, or less than or equal to about25 percent, less than about 20 percent, less than about 15 percent, lessthan about 10 percent, less than about 5 percent, or any number withinor any range within or including these values.

The predetermined period of time may be any suitable time period. Forexample, the increase in amplitude may occur for between about 1 secondto about 30 seconds. The predetermined period of time may be greaterthan about 1 second, greater than about 5 seconds, greater than about 10second, greater than about 15 seconds, greater than about 20 seconds,greater than about 25 seconds, or less than or equal to about 30seconds, less than about 25 seconds, less than about 20 seconds, lessthan about 15 seconds, less than about 10 seconds, less than about 5seconds, or any number within or any range including or within thevalues provided. Embodiments are contemplated where the amplitude boostoccurs more than once during a single brushing routine.

The AI mode may be beneficial where at least some of the contactelements comprise elastomeric elements which can provide gum massagingas well as polishing functions. With a larger amplitude, e.g.oscillation displacement angle, the elastomeric elements may provideboth functions, in some embodiments.

Additionally, embodiments are contemplated where the user selects the AImode via a push button on the handle. For example, if the user is awareof a problematic tooth from a cleaning standpoint, the user may depressthe pushbutton in order to increase the amplitude for a predeterminedperiod of time.

In some embodiments, the controller may allow the user to select anoperation mode where at least a portion of the contact elements have tipspeeds of at least 1.5 m/s. For convenience, the TS (tip speed) mode,e.g. normal mode. Embodiments are contemplated where a handle mayrecognize the refill attached thereto and adjust the PWM as required inorder to achieve the tip speed of 1.5 m/s in at least a portion of thecontact element field. For example, for a first refill, the controllermay adjust the PWM to a first level to achieve the 1.5 m/s in at least aportion of the contact elements. For a second refill, the controller mayadjust the PWM to a second level to achieve the 1.5 m/s in at least aportion of the contact elements, wherein the first level and the secondlevel are different. So, if the first refill has a larger radius thanthe second refill, either amplitude and/or frequency may be lower thanthe frequency and/or amplitude utilized for the second refill.Additionally, where the refill is recognized by the handle and/or thedisplay, the PWM may be adjusted based upon the type of contact elementspresent on the refill. For example, for a first refill comprising onlybristle tufts, the at least 1.5 m/s may be achieved by increasing theamplitude and/or frequency. In contrast, for a second refill havingelastomeric elements suitable for polishing the at least 1.5 m/s may beachieved by increasing the increasing the frequency and decreasing theamplitude (see the FI/AD mode discussed hereafter). Such communicationbetween the handle, the refill, and/or a display are disclosed in U.S.Pat. Nos. 7,086,111; 7,673,360; and 7,024,717; and in U.S. PatentApplication Publication Nos. 2008/0109973A1; 2010/0170052A1; and2010/0281636A1.

In some embodiments, the controller may allow an operation mode to beselected by the user which is for the purpose of performing a soft orsensitive operation. For convenience, the AD (amplitude decrease) mode.The AD mode may comprise a reduction in amplitude from desired amplitudefrom between about 5 percent to about 50 percent. Any suitable reductionmay be utilized. For example, the reduction in the amplitude may begreater than about 5 percent, greater than about 10 percent, greaterthan about 15 percent, greater than about 20 percent, greater than about25 percent, greater than about 30 percent, greater than about 35percent, greater than about 40 percent, greater than about 45 percent,or less than or equal to about 50 percent, less than about 45 percent,less than about 40 percent, less than about 35 percent, less than about30 percent, less than about 25 percent, less than about 20 percent, lessthan about 15 percent, less than about 10 percent, or any number withinor any range including or within the values provided. In the AD mode,the controller may increase the frequency above that of the desiredfrequency (discussed heretofore) such that the 1.5 m/s tip speed ismaintained by at least a portion of the contact elements, in someembodiments. In other embodiments, the AD mode may maintain theoperational frequency from desired frequency and simply reduce theamplitude as discussed above.

In some embodiments, the controller may allow the user to choose anoperation mode which is a gum care mode. For convenience, the AV(amplitude variation) mode. The AV mode may comprise a variation of theamplitude which occurs at predetermined time intervals. The variation ofthe amplitude can be between greater than about 25 percent of thedesired amplitude to about a reduction of about 50 percent of desiredamplitude. Any suitable variation in amplitude may be utilized. Forexample, the variation for the increase in amplitude may be greater thanabout 5 percent, greater than about 10 percent, greater than about 15percent, greater than about 20 percent, or less than or equal to about25 percent, less than about 20 percent, less than about 15 percent, lessthan about 10 percent, less than about 5 percent, or any number withinor any range within or including the values provided. With regard to thedecrease in amplitude, the variation may be greater than about 5percent, greater than about 10 percent, greater than about 15 percent,greater than about 20 percent, greater than about 25 percent, greaterthan about 30 percent, greater than about 35 percent, greater than about40 percent, greater than about 45 percent, or less than or equal toabout 50 percent, less than about 45 percent, less than about 40percent, less than about 35 percent, less than about 30 percent, lessthan about 25 percent, less than about 20 percent, less than about 15percent, less than about 10 percent, or any number within or any rangewithin or including the values provided.

As stated previously, the variation in the amplitude can occur atpredetermined intervals. Any suitable time period may be selected. Forexample, the variation may occur greater than about every 1 second,greater than about every 5 seconds, greater than about every 10 second,greater than about every 15 seconds, greater than about every 20seconds, greater than about every 30 seconds, or any number or rangewithin or including these values.

The variation of the amplitude may occur at any suitable time during thebrushing routine. For example, the amplitude variation may occur priorto the normal brushing routine by the user. As another example, thevariation can occur after the brushing routine of the user. As anotherexample, the variation may occur during the brushing routine of theuser.

The variations in amplitude may alternate between an increase in theamplitude above the desired amplitude followed by a decrease inamplitude below the desired amplitude. For example, in a first cycle,the amplitude may be increased by about 20 percent above a desiredamplitude, and in a second cycle the amplitude may decrease by about 30percent below the desired amplitude. In some embodiments, the increasein amplitude above the desired level may be the same as the value ofdecrease below of the desired level. For example, in a first cycle, theamplitude may be increase by about 20 percent above the desiredamplitude, and in a second cycle the amplitude may be decrease by about20 percent below the desired amplitude.

The variation of the amplitude may have any suitable time duration. Forexample, when the amplitude is either increased or decreased from thedesired amplitude, the change in amplitude may last for a time period ofgreater than about 1 second, greater than about 5 seconds, greater thanabout 10 seconds, greater than about 20 seconds, greater than about 25seconds, greater than about 30 seconds, greater than about 35 seconds,greater than about 40 second, greater than about 45 seconds, greaterthan about 50 second, greater than about 55 second, greater than about60 second, or less than about 60 second, less than about 55 seconds,less than about 50 seconds, less than about 45 seconds, or less than orequal to about 40 seconds, less than about 35 seconds, less than about30 seconds, less than about 25 seconds, less than about 20 seconds, lessthan about 15 seconds, less than about 10 seconds, less than about 5seconds, or any number within or any range within or including thevalues provided.

In some embodiments, the time duration of the variation may depend uponwhether the variation is an increase or a decrease in the desiredamplitude. For example, in some embodiments, an increase in amplitudeabove the desired amplitude may have a first time duration while adecrease in amplitude below the desired amplitude may have a second timeduration. In some embodiments, the first time duration may be the sameas the second time duration. In some embodiments, the first timeduration may be different than the second time duration. For example,the first time duration may be longer than the second time duration. Asyet another example, the second time duration may be longer than thefirst time duration.

In some embodiments, the increases and/or decreases may be arranged inany suitable manner. For example, in some embodiment, a first increasemay occur at a first predetermined time period and last a first timeduration. After the first time duration, the amplitude may return to thedesired level for a predetermined time period. Subsequently, a secondincrease may occur at a second predetermined time and last for a secondtime duration. After the second time duration, the amplitude may againreturn to the desired level or may decrease. The subsequent adjustmentof the amplitude may be another increase or a decrease from the desiredamplitude. Similarly, any decreases in amplitude from the desiredamplitude may occur as described above with regard to the first increaseand the second increase.

Any number of combinations may be created. For example, an increasefollowed by a decrease, an increase followed by an increase, a decreasefollowed by an increase, or a decrease followed by a decrease.Additionally, between any of the increases or decreases, the amplitudemay return to the desired amplitude.

In some embodiments, the controller may allow the user to select a modeof operation which comprises a change in both frequency and amplitude.For convenience, the FV/AV (frequency variation/amplitude variation)mode. The change in frequency can be any suitable increase or decrease.For example, in some embodiments, the frequency may increase above thedesired frequency by greater than about 5 Hz, greater than about 10 Hz,greater than about 15 Hz, greater than about 20 Hz, greater than about25 Hz, greater than about 30 Hz, or less than or equal to about 30 Hz,less than about 25 Hz, less than about 20 Hz, less than about 15 Hz,less than about 10 Hz, less than about 5 Hz, or any numbers within orany ranges within or including the values provided.

Similarly, the change in frequency may be a decrease from the desiredfrequency. For example, in some embodiments, the frequency may decreaseby greater than about 5 Hz, greater than about 10 Hz, greater than about15 Hz, greater than about 20 Hz, greater than about 25 Hz, greater thanabout 30 Hz, or less than or equal to about 30 Hz, less than about 25Hz, less than about 20 Hz, less than about 15 Hz, less than about 10 Hz,less than about 5 Hz, or any numbers within or any ranges within orincluding the values provided.

Also, the amplitude may be any suitable increase or decrease. Forexample, in some embodiments, the amplitude may increase or decreasewith regard to the desired amplitude as described heretofore with regardto the AV mode. Similarly, the time periods of variation as well as thetime periods for the duration of these changes to frequency and/oramplitude may be as described with regard to the AV mode. Additionally,an increase in frequency may be accompanied by an increase in amplitudein some embodiments. In other embodiments, an increase in frequency maybe accompanied by a decrease in amplitude. In other embodiments, anincrease in amplitude may be accompanied by a decrease in frequency.And, in other embodiments, a decrease in amplitude may be accompanied bya decrease in frequency.

In some embodiments, the controller may allow the user to select a modeof operation which may be suitable for tongue cleaning. For convenience,FI/AD2 (frequency increase/amplitude decrease) mode. The increase infrequency above that of the desired frequency may be as described withregard to the FV/AV mode. The AD2 portion of the FI/AD2 mode maycomprise any suitable reduction in amplitude from the desired range ofamplitudes. The FI/AD2 mode may comprise a reduction in amplitude fromdesired amplitude from between about 5 percent to about 75 percent. Forexample, the reduction in the amplitude may be greater than about 5percent, greater than about 10 percent, greater than about 15 percent,greater than about 20 percent, greater than about 25 percent, greaterthan about 30 percent, greater than about 35 percent, greater than about40 percent, greater than about 45 percent, greater than about 50percent, greater than about 55 percent, greater than about 60 percent,greater than about 65 percent, greater than about 70 percent, or lessthan or equal to about 75 percent, less than about 70 percent, less thanabout 65 percent, less than about 60 percent, less than about 55percent, less than about 50 percent, less than about 45 percent, lessthan about 40 percent, less than about 35 percent, less than about 30percent, less than about 25 percent, less than about 20 percent, lessthan about 15 percent, less than about 10 percent, or any number orrange including or within these values.

Because tongue cleaning may occur after the course of a brushingroutine, the FI/AD2 mode may begin automatically after a predeterminedamount of time, i.e. after the brushing routine. For example, the FI/AD2mode may begin after about two minutes or after about three minutes, orany number or any range within or including these values.

In some embodiments, the controller may allow the user to select a modeof operation which may be suitable for polishing teeth. For convenience,HF/AD, (high frequency/amplitude decrease) mode. The increase infrequency may be any suitable increase. For example, the frequency mayincrease by greater than about 25 percent over that of the desiredfrequency, greater than about 30 percent, greater than about 35 percent,greater than about 40 percent, greater than about 45 percent, greaterthan about 50 percent, greater than about 60 percent, greater than about70 percent, greater than about 80 percent, greater than about 90percent, greater than about 100 percent, or less than about 100 percentless than about 90 percent, less than about 80 percent, less than about70 percent, less than about 60 percent, less than about 50 percent, lessthan about 40 percent, less than about 30 percent, or any number orrange within or including these values. The decrease in amplitude fromthat of the desired amplitude may be as described heretofore with regardto the AD mode.

In some embodiments, the controller may allow the user to select a modeof operation which provides a massage function. For convenience, the FV(frequency variation) mode. The variation in frequency may be anysuitable amount. Some examples of the variation in frequency areprovided with regard to the FV/AV mode.

Embodiments are contemplated where the personal hygiene system ofcomprises storage (memory) capability. For example, a user may have asaved profile in which the amplitude is slowly increased duringbrushing. And, at the conclusion of the brushing session, e.g. twominutes, the frequency may be increased to perform a polishing and/orsealing function. In some embodiments, the controller may provide thisfunctionality without the use of a saved profile. In some embodiments,the polishing and/or sealing may occur at the beginning of the brushingsession.

Some of the modes may be offered to the user depending on the type ofrefill attached to the handle. For example, if a refill with a polishingelement is attached to the handle, the controller may allow only certainoperational modes to the user, e.g. HF/AD. Again, as mentionedpreviously, the handle and refill may include communication deviceswhich allow the handle to identify the refill. Also, embodiments arecontemplated where the personal hygiene device comprises a display whichis in signal communication with the handle and the refill. In suchembodiments, the display may provide instructions to the handle on whatoperation modes are available for a particular refill. Additionally, insome embodiments, the handle may recognize the refill and determinewhich modes are available for the refill. Communication between handles,refills, and/or displays, is described in U.S. Pat. Nos. 7,086,111;7,673,360; and 7,024,717; and in U.S. Patent Application PublicationNos. 2008/0109973A1; 2010/0170052A1; and 2010/0281636A1. Based on theforegoing, embodiments are contemplated where a user is allowed toselect an operational mode from a first set of operation modes for afirst refill and a second set of operation modes for a second refill,wherein the first set of operation modes and the second set of operationmodes are different. Communication between handle(s), refill(s), anddisplays, is discussed hereafter.

Handle and Refill

Referring to FIG. 6, the personal care attachment, e.g. refill, 21comprises the housing 20 described heretofore. Within the attachmenthousing 20, a drive member 640 resides. The drive member 640 has aproximal end 640A and a distal end 640B. The proximal end 640A maycomprise a first attachment element 615, and the distal end 640B maycomprise a connection 660. The connection 660 may be coupled to acontact element carrier, e.g. 22, 422. The contact element carrier 22,422 may be coupled to the attachment housing 20 as described in anapplication filed in the EPO entitled “ORAL HYGIENE IMPLEMENT AND ORALHYGIENE DEVICE”, filed on Jul. 25, 2011, and having attorney docketnumber Z-08589FQ. The contact element carrier 22, 422 may berotationally coupled to the attachment housing 20 such that when driven,the contact element carrier 22, 422 may move in an oscillating rotatingmanner.

The first attachment element 615 may comprise a permanent magnet or amagnetizable element such as a block of magnetizable iron or steel.Typically, austenitic steel is not magnetizable, while martensitic orferritic steel typically is magnetizable. The first attachment element615 may be disposed within a recess in the proximal end 640A of thedrive member 640.

As shown, the drive member 640 may reciprocate generally parallel to thelongitudinal axis 100 as shown by arrow 630. Because the connection 660is eccentric to a pivot 670, the reciprocating motion of the drivemember 640 causes the contact element carrier 22, 422 to rotate aboutthe rotational axis 95 (shown in FIG. 1C).

The drive member 640 should be relatively slim to allow it to fitcompactly within the attachment housing 20. In some embodiments, thedrive member 640 can be less than about 9 mm in diameter, less thanabout 8 mm in diameter, less than about 7 mm in diameter, less thanabout 6 mm in diameter, less than about 5 mm in diameter, less thanabout 4 mm in diameter, less than about 3 mm in diameter, less thanabout 2 mm in diameter, less than about 1 mm in diameter, or greaterthan about 1 mm in diameter, greater than about 2 mm in diameter,greater than about 3 mm in diameter, greater than about 4 mm indiameter, greater than about 5 mm in diameter, greater than about 6 mmin diameter, greater than about 7 mm in diameter, greater than about 8mm in diameter, or any number or any range including or within thevalues provided. Additionally, the drive member 640 should bemechanically stable and be capable of transmitting forces of about 10 N.Also, the drive member 640 should have a natural frequency of at least200 Hz, greater than about 225 Hz, greater than about 250 Hz, greaterthan about 275 Hz, or any number or any range including or within thevalues provided.

The diameter for the drive member 640 can impact the size of the housingof the refill adversely. For example, if the diameter of the drivemember 640 is chosen too high, then the housing for the refill willgenerally be too large which consumers may perceive as too cumbersome.While smaller diameters for the drive member 640 are desired, the drivemember 640 should also be designed to withstand the forces transferredfrom the drive during operation.

The drive member 640 may comprise any suitable material. Some examplesinclude polyoxymethlylene (POM), polyamide (PA), or polybutyleneterephthalate (PBT). In some embodiments, additional reinforcement maybe added to the drive member 640. For example, reinforcement fibers,e.g. Kevlar™ fibers may be added to the material of the drive member640. Any other suitable reinforcement fibers may be added. Additionally,the drive member 640 may comprise a shape which is constructed to reducethe likelihood of buckling. For example, the drive member 640 maycomprise a cross section which is in the shape of a cruciform, a Y, orany other suitable shape.

For those embodiments where the drive member 640 comprises a crosssectional shape which is non-circular, the values provided above withregard to the diameter of the drive member 640 may still apply. Forexample, a drive member 640 comprising a cruciform cross section shouldnot cross the boundary of a circle having a 6 mm diameter, or in someembodiments 5 mm, or 4 mm, or 3 mm, and so on.

As stated previously, in some embodiments, toothbrushes may have anoperating frequency of greater than about 120 Hz. With such frequencies,it is important that the personal care attachment, e.g. refill 21, has aresonance frequency which is greater than that of the operatingfrequency, in some embodiments. If the resonance frequency of the refill21 is too close to the desired frequency, then during operation,resonance motions may be induced in the refill 21. For example, therefill 21 or the drive member 640 may experience side to side motion.This side to side motion may cause some discomfort to the user and/oradditional noise generation during operation.

For those embodiments where resonance motions are not desirable, theresonance frequency of the refill 21 may be greater than about 125percent of the desired frequency. However, for those refills which areamenable to the HF/AD, FI/AD2, and FV/AV, operational modes, theresonance frequency of the refill may be greater than about 175 percentof the operating frequency, greater than about 200 percent, greater thanabout 225 percent, greater than about 250 percent, greater than about275 percent, greater than about 300 percent, or less than or equal toabout 300 percent, less than about 275 percent, less than about 250percent, less than about 225 percent, or any number or range includingor within the values provided. For those embodiments where resonancemotions are desired, then the refill may be designed to have a resonancefrequency which is closer to the desired frequency.

The resonance frequency of the refill 21 or any part thereof may bedetermined by any suitable method. For example, computer software may beutilized to determine the resonance frequency of the refill 21 or anypart thereof. A suitable brand of software is Pro/ENGINEER® MechanicaWildfire® 4.0.

FIG. 7 shows a longitudinal cut through a handle 712. The handle 712 maybe constructed similar to the handle 12 described with regard to FIGS.1A and 1B. In the shown embodiment, the handle 712 comprises a driveshaft 740 that functions as a movable motor part of a linear drive 760.The linear drive 760 is disposed within the handle 712. Duringoperation, the linear drive 760 cause the drive shaft 740 to reciprocatein a direction which is generally parallel to the longitudinal axis 99(shown in FIG. 1B). The reciprocating linear movement of the drive shaft740 as is indicated by double arrow 797. In the shown embodiment, thedrive shaft 740 may be prolonged by an extender element 719 that forms apart of the drive shaft 740. The extender element 719 can provide anincrease in diameter with respect to the diameter of the drive shaft740. A recess 711 may be provided in the extender element 719 foraccommodating a second attachment element 715.

The second attachment element 715 may be attached to the drive shaft 740by any suitable method. For example, instead of being accommodated inthe extender element 719, the second attachment element 715 may bedirectly secured at the drive shaft 740. In embodiments where the secondattachment element 715 is a magnet, or magnetisable material, the driveshaft 740 may be made at least at its tip portion from a permanentmagnetic material, which tip would then form the second attachmentelement 715.

The second attachment element 715 has a coupling side 721 intended forgetting into contact with a respective coupling side 621 (shown in FIG.6) of the first attachment element 615 of the refill 21 when beingattached.

In embodiments where the second attachment element 715 comprise a magnetand/or magnetisable material, the second attachment element 715 may be acylindrical shape having its cylinder axis essentially oriented parallelto the longitudinal axis 99 (shown in FIG. 1B) of the handle 712. Thediameter of the cylinder may be chosen to be about or larger than about2 mm, larger than about 3 mm, larger than about 4 mm, larger than about5 mm, or larger than about 6 mm or any individual number or any rangesincluding or within the values provided.

In those embodiments where the second attachment element 715 is a magnetand/or a magnetisable material, the second attachment element 715 mayhave any suitable shape. In such embodiments, the second attachmentelement may have a surface area which is similar to that of thoseembodiments where the second attachment element 715 is cylindrical inshape.

Any suitable height of the second attachment element 715 may be chosen.For example, the height may be chosen to be about or larger than 2 mm,larger than about 3 mm, larger than about 4 mm, larger than about 5 mm,or larger than about 6 mm, or any number or range within or includingthese values. In some embodiments, the height may be chosen as large asthe diameter. In those embodiments where the first attachment element615 (shown in FIG. 6) comprises a magnet and/or a magnetisable material,the first attachment element 615 may be constructed similar to thesecond attachment element 715 described above.

Referring to FIGS. 6 and 7, for those embodiments where the firstattachment element 615 and the second attachment element 715 comprisemagnets and/or magnetisable material, a magnetizable element (e.g. amagnetizable steel or iron element) can be realized relatively cheap.This aspect may be suitable for an attachment section, e.g. refill 21intended for disposal after a period of use may then be realizedrelative cheap. In contrast, a permanent magnet may be more expensive toprovide. However, a permanent magnet in the refill 21 together with apermanent magnet in the handle 712 can provide for a higher couplingstrength than a permanent magnet and magnetizable element combination atthe same construction having the same volume as the permanent magnetcombination of the former. As such a trade off exists between the costversus the strength of connection versus the space requirements. Forexample, the utilization of a magnetisable element, in order to achievethe strength of connection provided below, may require more volume.

For those embodiments where the first attachment element 615 and thesecond attachment element 715 comprise magnets and/or magnetisablematerial, in the attached state, their connection may be designed towithstand a separation force of at least about 2 Newton, of at leastabout 4 Newton, of at least about 6 Newton, of at least about 8 Newton,of at least about 10 Newton, or any individual number or any rangeincluding or within the values provided above. The connection betweenthe first attachment element 615 and the second attachment element 715as well as their constructions is discussed further in an applicationfiled in the EPO entitled “ATTACHMENT SECTION FOR AN ORAL HYGIENEDEVICE”, filed on Jul. 25, 2011, and having attorney docket numberZ-08584FQ.

At least one benefit of the magnetic coupling of the first attachmentelement 615 and the second attachment element 715 is that magneticcouplings are not tolerance based. As such, during operation, themagnetic coupling structure proposed heretofore may reduce the soundintensity level produced by the personal care device during operation.

Still referring to FIGS. 6 and 7, the handle 712 comprises a handlehousing 750 within which the drive system 760 is disposed. The handle712 may further comprise an attachment section 714. The attachmentsection 714 may comprise a second coupling structure 751 which couplesto a first coupling structure 650 provided at the refill 21. In someembodiments, the second coupling structure 751 may be rigidly coupled tothe housing 750 such that the second coupling structure 751 does notmove relative to the housing 750. In such embodiments, the drive shaft740 provides reciprocal linear motion to the drive member 640 within therefill 21.

Referring to FIGS. 6 through 8, in some embodiments, the second couplingstructure 751 is, in addition to the drive shaft 740, driven in areciprocating linear fashion. The second coupling structure 751 may becoupled to a second armature 780 which linearly oscillates with respectto the housing 750. In such embodiments, the drive member 640 is drivenas well as the attachment housing 20. For these embodiments, the driveshaft 740 and the second coupling structure 751 may be driven inopposite phases, e.g. 180 degrees out of phase. As such, the drive shaft740 may be moving in a first direction generally along the longitudinalaxis 99 (shown in FIG. 1B) or generally parallel thereto while thesecond coupling structure 751 is moving in a second direction along orgenerally parallel to the longitudinal axis 99 (shown in FIG. 1B). Thefirst direction and the second direction can be opposite one another.

At least one advantage of such embodiments is that because of the out ofphase linear reciprocation, the vibrations provided to the handlehousing 750 because of the movement of the drive shaft 740 may beoffset, at least in part, by the portion of the drive system 760 whichdrives the second coupling structure 751. Reduced vibrations to thehandle can similarly lead to less noise generation, i.e. less soundintensity during operation. Additional noise dampening elements arediscussed hereafter.

Additionally, in some embodiments, a drive system which can be utilizedin the present invention may eliminate the need for bush bearings orrolling bearings for support of the drive shaft which can alsocontribute to a reduction in noise generation during operation. FIG. 14shows a further embodiment of a linear electric motor. The featuresdescribed heretofore with regard to FIG. 7 may be combined with thefeatures of FIG. 14 and vice versa.

A drive shaft 2450 may extend along a longitudinal axis of the handle2400. The drive shaft 2450 is mounted to the housing by a mountingspring 2451. The mounting spring 2451 can be attached to the drive shaft2450 adjacent a first end 2452 of the drive shaft 2450. The firstmounting spring 2451 may be a leaf spring and may generally comprise acircular shape allowing the drive shaft 2450 to perform an oscillatingmotion in a direction 2453. Due to its design, the mounting spring 2451,in a direction perpendicular to the direction 2453 of motion of thedrive shaft 2450, provides a stable support of the drive shaft 2450.

An outer armature 2454 comprises two parts 2454A, 2454B on each side ofthe drive shaft 2450. The two parts 2454A and 2454B can be attached toeach other, such that they move as a single part. The outer armature2454 can form a channel 2455 between its two halves 2454A and 2454B. Thedrive shaft 2450 extends through this channel 2455 of the halves 2454Aand 2454B of the outer armature 2454. The drive shaft 2450 and the outerarmature 2454 can experience an oscillating motion along the same path2453 during operation.

The outer armature 2454 is mounted via a second mounting spring 2456 tothe housing. While the housing is attached to an outer portion of twomounting springs (2451, 2456) the drive shaft 2450 and the outerarmature 2454, respectively are mounted to an inner mounting section ofthe mounting springs 2451, 2456.

The second mounting spring 2456 is attached adjacent a second end 2475or side of the outer armature 2454 which is opposite to the first end2452 of the drive shaft 2450. When the drive shaft 2450 and outerarmature 2454 move 180 degrees out of phase, the retraction forcestransferred from each of the two mounting springs 2451, 2456 onto thehousing should compensate each other, at least in part. Namely, theforces transferred to the housing should cancel each other out or atleast a portion thereof such that vibrations felt by the user grippingthe housing are greatly reduced and/or precluded.

The drive shaft 2450 and outer armature 2454 may be coupled to eachother via two coupling springs 2457, 2458. Each of the two couplingsprings 2457, 2458 may comprise two leaf springs 2459 which can be leafsprings which are circular in nature (similar to spring 2451). Acombination of two springs 2459 for each of the two coupling springs2457, 2458 may be chosen to be able to easily vary the spring constantof the composed springs 2457, 2458. The drive shaft 2450 is mounted toan inner section of the springs 2459 while the outer armature 2454 ismounted to an outer section of the springs 2459.

A coil 2462 can be attached to the housing providing an interaction withthe outer armature 2454. The outer armature 2454 may further comprise aset of four permanent magnets 2463 in order to allow a magnetic and/orelectrical coupling between the outer armature 2454 and the coil 2462 atthe housing. Embodiments are contemplated where greater than fourpermanent magnets are utilized. Embodiments are also contemplated whereless than four permanent magnets are utilized.

The spring constants of the coupling springs 2457 and 2458 may be chosensuch that their resonance frequency corresponds to the oscillationfrequency which is imposed by the electric drive consisting of the coil2462 and the magnets 2463.

In order to provide an oscillating motion, the current flow through thecoil 2462 can be controlled such that it is intermittent. The currentflow can be interrupted when the drive shaft 2450 and the outer armature2454 reach the maximum amplitude of their oscillating motion. Thecoupling springs 2457, 2458 as well as the two mounting springs 2452,2456 then can force the drive shaft 2450 and the outer armature 2454back to their respective starting positions.

Each of the drive shaft 2450 and the outer armature 2454 comprisesconnectors 2460, 2461 for coupling the linear electric motor tofunctional elements of a household appliance. Such connectors werediscussed heretofore with regard to FIGS. 6-8. And, as statedpreviously, the connectors described in FIGS. 6-8 may be utilized in theembodiment described in FIG. 14.

Additional motors which may be suitable for use in the personal caredevice of the present invention are described in an application filed inthe EPO entitled “ATTACHMENT SECTION FOR AN ORAL HYGIENE DEVICE”, filedon Jul. 25, 2011, and having attorney docket number Z-08584FQ; in anapplication filed in the EPO entitled “RESONANT MOTOR UNIT AND ELECTRICDEVICE WITH RESONANT MOTOR UNIT”, filed on Jul. 25, 2011, and having anattorney docket number Z-08572FQ; in an application filed in the EPOentitled “LINEAR ELECTRIC MOTOR”, having a filing date of Jul. 25, 2011,and an attorney docket number of Z-08486MQ; in an application filed inthe EPO entitled “HANDLE SECTION OF A SMALL ELECTRIC DEVICE AND SMALLELECTRIC DEVICE”, having a filing date of Jul. 25, 2011, and an attorneydocket number of Z-08585FQ; and in a patent application filed in theUnited States entitled, “LINEAR ELECTRO-POLYMER MOTORS AND DEVICESHAVING THE SAME”, having a filing date of Jul. 25, 2011, and having anattorney docket number of Z-08597P.

In some embodiments, a drive system comprising a motor providingrotational energy to a refill can be utilized. These motors maysimilarly accomplish the higher frequencies because they may be utilizedas direct drives as opposed to intervening gearing in conventionalbrushes. Such motors are described in U.S. Patent ApplicationPublication No. US2010/0277013; and EP publication nos. EP2262084;EP2262085;.

Regardless of the motor utilized, the motor should have a largerresonance frequency than the desired frequency. Once a refill is addedto the motor, then the resonance of the overall system will generallyfall below that of the desired frequency. A difference between thedesired frequency and the resonance frequency of the overall system isat least 5 Hz, at least 10 Hz, at least 15 Hz, or at least 20 Hz, or atleast 30 Hz, at least 40 Hz, or at least 50 Hz, or any number or anyrange including or within these values. In some embodiments, the drivefrequency is higher than the theoretical resonance frequency of thesystem.

Theoretical resonance frequency is determined via the followingequation.

$f = {\frac{1}{2\pi}*\sqrt{\frac{k}{2I}}}$

Where k=spring constant and I is the mass and/or the mass inertiamoment. For example, in the case where the rotational motor is used, noactual springs are present within the motor; however, reluctance forcescan act similar to springs and therefore should be accounted for whencalculating the resonance frequency. Other suitable methods may beutilized to determine the resonance frequency of the toothbrush or anyparts thereof. For example, computer software may be utilized todetermine the resonance frequency of toothbrush or any parts thereof,including the refill. A suitable brand of software is Pro/ENGINEER®Mechanica Wildfire® 4.0.

In the rotational motor, the magnetic reluctance force is used as aspring effectively to reset the movement of the drive shaft. The magnetswithin the motor, which provide the magnetic reluctance force may bedesigned so that the magnetic reluctance force is linear over an area ofplus/minus about 2 mm or plus/minus about 20 degrees of rotation of theshaft. The reluctance force utilized in rotational motors is discussedin additional detail in US2010/0277013; EP publication nos. EP2262084;and EP2262085.

Pumping Effect As mentioned heretofore, it is believed that beneficialliquid flows occur in the oral cavity where at least a portion of thecontact elements have a tip speed of at least about 1.5 m/s. Thepressure on the fluid can be described by the following equation.

P=0.5 ρν

where ρ=density (assume density of water at standard temperature andpressure) and ν=velocity (tip speed). Based on the previous discussion,a first plurality of contact elements adjacent the rotational axis havea lower tip speed than does a second plurality of contact elements whichare positioned further outboard of the rotational axis. As such, thevelocity pressure exerted on the fluid by the first plurality is lessthan that of the second plurality. Without being bound by theory, it isbelieved that the pressure differential from the first plurality to thesecond plurality tends to act as a pump. For example, it is believedthat adjacent the first plurality of contact elements the fluid tends tobe sucked up by the first plurality of contact elements. Further, it isbelieved that the fluid is distributed to the second plurality ofcontact elements where the fluid is then pumped away from the secondplurality of contact elements onto the various oral cavity surfaces.Such pumping of fluid is believed to loosen coatings, e.g. plaque, onthe teeth.

In laboratory tests it has been shown that bacteria can be loosenedthrough the shearing force of fluids. It has also been found that notonly removal of the bacteria coatings, but also rinsing and control ofthe composition of the plaque are important. Bacterial dental coatingseasily occur in the oral cavity and grow on the gum margin and gumpockets. Bacteria proliferate in these pockets. During their metabolism,the bacteria produce toxins, known as ectotoxins or endotoxins which cancause gum inflammations. It is difficult for one to remove the bacteriaas the filaments of conventional brushes cannot penetrate deeply enoughinto the gum pockets. Through rinsing the cell toxins are removed andthe gums recover. Through rinsing, the oxygen partial pressure in thefluid also increases in the gum pockets. In this way anaerobic bacteriawhich live in the absence of oxygen breed less quickly and aresuppressed by less harmful germs. Additionally, many toothpastes containantibacterial substance(s) in addition to fluorides. Through the flowsand built-up pressure toothpastes can penetrate deeper into the biofilmor the pockets and thus achieve a considerably better effect. Thiseffect also leads to recovery of the gum tissue and a reduction ininflammation.

Because the second plurality of contact elements are positioned furtheraway from the rotational axis of the contact element carrier, the secondplurality of contact elements generally have more contact with the gummargin. And, as discussed above, it is believed that the fluid is pumpedaway from the second plurality of contact elements. As such, the pumpingof the fluid is believed to loosen bacterial coatings and provide therinsing effect which aids in the removal of cell toxins and increasingthe oxygen partial pressure in the fluid in the gum pockets.

In some embodiments, the fluid flow from the contact element carrier maybe radial from the contact element carrier. Additionally, in someembodiments, the flow may exit the contact elements at an angle of about45 degrees. Referring to FIG. 9, a contact element carrier 922 has arotational axis 920. The contact element carrier 922 may be constructedsimilar the contact element carriers 22, 422, 922, 1210, describedheretofore. Again, it is believed that the fluid flow is drawn to afirst plurality of contact elements 910 and is dispersed adjacent asecond plurality of contact elements 912. The fluid flow may exit thecontact elements at an angle 940 which is greater than about 5 degrees,greater than about 10 degrees, greater than about 20 degrees, greaterthan about 30 degrees, greater than about 40 degrees, greater than about45 degrees, greater than about 50 degrees, greater than about 60degrees, greater than about 70 degrees, greater than about 80 degrees,or less than about 90 degrees, less than about 80 degrees, less thanabout 70 degrees, less than about 60 degrees, less than about 50degrees, less than about 45 degrees, less than about 40 degrees, lessthan about 30 degrees, less than about 20 degrees, less than about 10degrees, or any number or any range including or within the valuesprovided.

Noise

As stated previously, toothbrushes of the present invention may have anoperating frequency of greater than about 120 Hz. Conventionaloscillating rotating brushes do not currently operate in this range.There are several potential problems with operating conventionaloscillating/rotating toothbrushes at frequencies at or above 120 Hz. Asstated previously, the handles of conventional brushes tend to havegearing therein to convert 360 degree motor shaft rotation to a limiteddisplacement angle in a drive shaft. Additionally, the refills for thesehandles tend to have gearing, springs, etc. for changing the directionof the motion from the drive shaft. A first issue is friction. At higheroperating frequencies, the gearing within the handle and/or gearingwithin the refill would tend to heat up. Eventually, premature failuremay occur in either the handle or the refill. A second issue is noisegeneration. At higher operating frequencies, the gearing in the handleand/or the refill tends to make more noise. The increase in noisegeneration can be unpleasant to consumers.

For toothbrushes of the present invention, the elimination of gearing inthe handle and/or refill can reduce the noise generation at operatingfrequencies of greater than about 120 Hz. Referring again to FIG. 7, thedrive system 760 as configured does not need additional bearings for theshaft 740 or for the second armature 780. Instead leaf springs can beutilized between the shaft 740 and the second armature 780; between theshaft 740 and the housing 750; and between the second armature 780 andthe housing 750. Because of the reduced number of moving parts, thehandle 712 can produce less noise at higher operating frequencies thandoes a conventional toothbrush.

Additionally, the drive system 760 is a direct drive system. As such,the shaft 740 connects directly to the refill 21 without any interveninggearing. This helps reduce the sound intensity generation duringoperation.

Referring back to FIGS. 6 and 7, the refill 21 may similarly help reducethe noise produced by the toothbrush in the assembled state. Inconventional refills typically a mechanical coupling such as a snapconnection is utilized between the handle and refill. The snapconnection has inherently tolerance-based clearances or gaps between thecoupling partners so that the coupling partners may move relatively toeach other when the respective connection is established between partsdriven during operation. Such a mechanical connection is then prone togenerate unwanted noise during operation.

In contrast, in some embodiments, the first attachment section 615attaches to the second attachment section 715 via magnetic attraction.Because a magnetic connection is not tolerance based, the magneticconnection may be prone to produce less noise at operating frequenciesof greater than about 120 Hz.

In addition to the attachment mechanism between a refill and handle, adrive mechanism of a refill can contribute to the generation of noise aswell. Described below are some additional measures which may reduce thesound intensity levels when implemented in a refill. Accordingly, thefeatures described hereafter may be combined with the features of therefill 21 previously described and vice versa. Referring to FIG. 10, across section of a refill 1021 is shown. In some embodiments, the refill1021 may comprise a shaft element 1300 having a pivot pin 1301 coupledto a carrier 1210 of the functional element of the oral hygieneimplement in the horizontal plane H when being in the neutral position.

The horizontal plane H passes through an axle 1240 which is therotational axis of the contact element carrier 1210. And, the horizontalplane H is perpendicular to the longitudinal axis L of the refill 1021.The longitudinal axis L is the longest dimension of the refill 1021which bisects the housing 1290 in the plane shown in FIG. 10.

A fixation element 1230 is secured at the housing 1290 at two locationsthat are opposite with respect to the axle 1240 that is supported in thecentre of the fixation element 1230. The housing 1290 may comprise aninwardly extending portion 1295 to which the fixation element 1230 issupported to generally allow for a small angular offset between ageneral extension direction L3 of the fixation element 1230 and alongitudinal extension direction L of the oral hygiene implement (theextension direction L3 is defined by the two mounting locations).

In the shown embodiment, the fixation element 1230 does not extendsymmetrically along the connecting line L3 between the two mountinglocations. Instead, the fixation element 1230 is curved in such a mannerthat it is concave with respect to the direction from which the pivotpin 1301 approaches when moving in positive angular direction (i.e.toward the maximum oscillation angle +θ). This allows for a largermaximum oscillation angle. The effective extension direction of thefixation element 1230 is indicated by L3′. As is shown, the fixationelement 1230 may be symmetrically curved with respect to the centre axisdefined by the axle 1240. Here, curved shall include stepped designs ofthe fixation element 1230.

It was discovered that the orientation of the pivot pin 1301 withrespect to the horizontal axis H can contribute to the noise generatedwhen the refill 1021 is in operation. For example, an imaginary radialarm 1041 is defined by a distance between a center point of the pivotpin 1301 and a center point of the axle 1240. When the radial arm 1041is colinear with the horizontal axis H, in the neutral position of thesystem, the relative noise generation during operation is low. However,when the radial arm 1041 is moved to away from the horizontal axis H,noise generation tends to increase during operation. If the radial arm1041 were positioned such that the radial arm 1041 were co-linear withan offset arm 1043 an angle 1051 would exist between the radial arm 1041and the horizontal axis H. In order to decrease the noise generated bythe refill 1021 during operation, the angle 1051 can be about zerodegrees, greater than about 2 degrees, greater than about 4 degrees,greater than about 5 degrees, greater than about 8 degrees, greater thanabout 10 degrees, greater than about 15 degrees, greater than about 20degrees, greater than about 25 degrees, greater than about 30 degrees,greater than about 35 degrees, greater than about 40 degrees, or lessthan about 40 degrees, less than about 35 degrees, less than about 25degrees, less than about 20 degrees, less than about 15 degrees, lessthan about 10 degrees, less than about 5 degrees, less than about 2degrees, or any number or any range within or including the valuesprovided above.

The angle described above is not limited to being subjacent to thehorizontal axis H. In some embodiments, the angle between the radial arm1041 and the horizontal axis H can be superjacent to the horizontal axisH.

Without being bound by theory, it is believed that for angles greaterthan about 45 degrees, the forces acting on the pivot pin 1301 are splitin a disadvantageous manner. For example, consider that the force actingon the shaft element 1300 tends to act along the longitudinal axis L ofthe refill 1021. For orientations of the pivot pin greater than 45degrees, less than half of the applied force to the pivot pin 1301 isbeing utilized to move in a direction which is parallel to thelongitudinal axis L. As such, more than half of the applied force iswasted. It is believed that this wasted force creates additional heatand noise.

Additional measures may be taken in the handle 712 to reduce the noiseemitted by the toothbrush. For example, a noise abatement material maybe positioned between the second armature 780 and the housing 750. Forexample, a lead tape may be placed within the housing in order to reducethe noise output from the brush. Additionally, in embodiments where thesecond armature 780 does not move relative to the housing 750, the leadtape may also serve to reduce the vibrations experienced by a userduring use.

Various prototypes and conventional power toothbrushes were tested todetermine noise levels. Each of the toothbrushes were tested inaccordance with the test method as described below. In a firstcomparison, a conventional power toothbrush handle without a refill wastested at its normal operating speed and then boosted to a drivefrequency which is comparable to that of the prototypes described in theembodiments herein. Table 1 provides the results of the testing.

The conventional brushes tested comprised handles and refills. Theconventional handles included rotational motors. The conventionalhandles tested are similar to the Oral-B® Professional Care 1000 andOral-B® Professional Care 3000 series of power handles. The refills usedin the testing for the conventional handles as well as the prototypehandles with the rotational motors was the Oral-B® Precision Clean.

TABLE 1 Tested operating Sound Type of handle frequency level dB(A)Conventional  88 Hz 72.4 Conventional 172 Hz 82.9 Prototype withrotational 163 Hz 55.3 motor without idle run state Prototype withrotational 163 Hz 40.3 motor with idle run state Prototype with linearmotor 152 Hz 42 without idle run state Prototype with linear motor 152Hz 44.2 with idle run state

As shown in Table 1, both the prototypes either with a rotational motoror a linear motor produced lower noise in normal operation than did theconventional brush at either operating frequency. The conventionaltoothbrush handle was modified for the testing at 172 Hz. Specifically,the power source for the motor was modified to provide the requisitevoltage in order to achieve the higher operating frequency in theconventional toothbrush handle.

It is expected based upon the values that for frequencies below 163 Hzand 152 Hz that the prototypes tested would produce lower soundintensities. Based on the findings in Table 1, the handles constructedin accordance with the present invention may operate at frequenciesgreater than 120 Hz, and as described previously, while producing lessthan about 80 dB(A) sound intensity. In some embodiments, the handlesmay operate at a frequency of greater than about 120 Hz while producinga sound intensity of less than about 75 dB(A), less than about 70 dB(A),less than about 65 dB(A), less than about 60 dB(A), less than about 55dB(A), less than about 50 dB(A), less than about 45 dB(A), less thanabout 40 dB(A), less than about 35 dB(A), less than about 30 dB(A), orgreater than about 30 dB(A), greater than about 35 dB(A), greater thanabout 40 dB(A), greater than about 45 dB(A), greater than about 50dB(A), greater than about 55 dB(A), greater than about 60 dB(A), greaterthan about 65 dB(A), greater than about 70 dB(A), or any number or anyrange within or including these values.

Also shown in Table 1, at least one of the rotational motor prototypesand one of the linear motor prototypes include the idle run statefeature. For the idle run state feature, the frequency was kept atnormal operating frequency; however, the amplitude exhibited by thedrive shaft was reduced below that of the respective prototypes withoutthe idle run state feature. The prototype with the rotational motorexhibited the behaviour that would generally be expected, i.e. withdecreased amplitude decreased noise. The values for the rotational motorprototype reflect this, i.e. 55.3 dB(a) versus 40.3 dB(A).

Regarding the linear drive prototypes, the sound intensity between theidle run state prototype and the non-idle run state prototype is amarginal difference. It is believed that because of the extremely lowsound intensity level of the non-idle run state prototype, theimplementation of the idle run state did not appear to provideadditional reduction in sound intensity. Additionally, background noisecan have a larger impact on low sound intensities.

Additional noise testing was performed on conventional toothbrushes andprototypes. As shown in Table 2, the toothbrush handles were tested withrefills attached thereto in both an unloaded and a loaded condition. Theload applied to the refill in the loaded condition was 2 N. Also, thesame type of refill used for the conventional toothbrush was used on therotational motor prototypes; however, a prototype refill was utilized onthe linear motor prototypes.

TABLE 2 Tested Sound operating Sound level dB(A) - level dB(A) - Type ofhandle frequency unloaded 2N load Conventional  82 Hz 66.5 dB(A) 66.5dB(A) Conventional 153 Hz 77.9 dB(A) 76.5 dB(A) Prototype withrotational 164 Hz 65.8 dB(A) 63.3 dB(A) motor without idle run statePrototype with rotational 163 Hz   61 dB(A) 62.8 dB(A) motor with idlerun state Prototype with linear 152 Hz 62.3 dB(A) 58.8 dB(A) motorwithout idle run state Prototype with linear 152 Hz   52 dB(A)   60dB(A) motor with idle run state

Regarding the test results of the refill in the unloaded state, as shownin Table 2, with the refill attached, the sound intensities for the twoconventional toothbrush handles dropped compared to the values ofTable 1. It is believed that the attachment of the refill to theconventional toothbrush handles may reduce the existence of some of thetolerance based features of the handle. Accordingly, the sound intensitydrops with the attachment of the refill.

In the case of the tested prototypes the opposite occurred. With theattachment of the refills, the sound intensities actually increased.However, as stated previously, in an effort to reduce the soundintensity produced by the handles constructed in accordance with thepresent invention, the existence of tolerance based elements, e.g.bearings, has been reduced or eliminated. As such, the attachment of therefill to the prototypes does not have the same effect as the attachmentof a refill to a conventional handle does. Namely, the attachment of therefill to the prototype handle does not reduce the existence oftolerances because tolerance based elements have been reduced and/oreliminated in the prototype handles.

The refills constructed in accordance with the embodiments describedherein, in an unloaded state, should add no more than about 8 dB(A), nomore than about 10 dB(A), no more than about 12 dB(A) no more than about14 dB(A), no more than about 16 dB(A), no more than about 18 dB(A), orno more than about 20 dB(A), or any number or any range including orwithin the values provided.

With an applied load of 2 N, the conventional brush having an operatingfrequency of 153 Hz, emitted less sound intensity than in the unloadedstate. It is believed that the conventional refill utilized on theconventional handle similarly includes tolerance based elements asdiscussed heretofore. As such, the application of the 2 N load isbelieved to have decreased the size of the tolerances and thereforereduced the sound intensity.

Similarly, the rotational motor prototype, not having the idle run statefeature utilized similar refills as the conventional brush.Specifically, conventional refills were utilized on the rotational motorprototypes. As such, a decrease in sound intensity was also seen withthe applied load of 2N. Regarding the rotational motor prototype withthe idle run state feature, recall that in the unloaded state, theamplitude is reduced. In contrast, an applied load of 2 N causes thedrive system to increase the amplitude to the normal run state therebyincreasing the sound intensity.

Regarding the prototypes having the linear motors, the prototype withoutidle run state saw a decrease in the sound intensity under load. Recallhowever that the without idle run state, this prototype was operating ata desired frequency in a desired amplitude range even under no load. Assuch, when the load was applied, the amplitude was decreased. Thedecrease in amplitude may explain the reduction in sound intensity. Forthe prototype having the idle run state feature, an increase in soundintensity was seen. Recall that with the idle run state, when a load issensed, the amplitude is boosted to be within the desired amplituderange. As such, an increase in sound intensity occurred.

Device Communication

As stated previously, handles, refills, etc. may communicate with anexternal display. As shown in FIG. 13, an oral care system 2330comprising an electric toothbrush 2335, a base 2340 for receiving theelectric toothbrush 2335, and a visual and/or audio display 2345 that isin continuous and/or intermittent data communication with the electrictoothbrush 2335 and/or the base 2340 before, during, and/or after use bya consumer of the electric toothbrush 2335. The toothbrush 2335 maycomprise a handle 2336 and a refill 2337. Embodiments are contemplatedwhere the display 2345 comprises a wireless communication link with thehandle 2336, and/or the refit 2337.

The oral care system 2330 can use a variety of arrangements, singly orin combination, to implement data communication between the display 2345and the electric toothbrush 2335 and/or base 2340. In one embodiment,the toothbrush 2335 and/or the base 2340 are in wireless communicationwith the display 2345 via wireless data link 2355. The wireless datalink 2355 may be based upon a suitable short range radio frequencycommunication technology, such as Bluetooth, WiFi (802.11 based or thelike) or another type of radio frequency link, such as wireless USB at2.4 GHz. For radio transmissions, an antenna can be mounted on a printedcircuit board (PCB) disposed in the electric toothbrush 2335, base 2340,sleeve, and/or the display 2345.

For infrared (IR) transmissions, one or more IR transmitter diodes canbe mounted in the electrical toothbrush 2335, the handle 2336, the base2340, the sleeve, the refill 2337, and/or the display 2345. An IRwavelength suitable for use with the present invention is 950 nmmodulated at 36 KHz. Other wireless data communication technologies maybe used such as, for example, radio frequency transmission or cellulartransmission. In some embodiments, a plurality of oral care products maybe in data communication with the electric toothbrush 2335, the base2340 and/or the display 2345, as previously described. The data transfercan be one-way and/or two-way, continuous and/or intermittent,modulated, or any combination of the foregoing, between the display2345, the base 2340, electric toothbrush 2335, the handle 2336, therefill 2337, and/or any other personal care product. As previouslydescribed, the display 2345 can be configured to communicate using oneor more types (e.g., IP wireless radio, hard-wired, etc.) of datacommunication methods, and the same display 2345 can employ differenttypes of data communication methods with different personal careproducts.

In some embodiments, a data reader can be associated with a toothbrushin variety of ways. For example, the data reader can be provided in thetoothbrush handle 2336, a charging station, e.g. base 2340, a detacheddisplay 2355, or other detached device, a toothbrush stand, etc. In oneembodiment, a data transmitter can be provided as a radio frequencyidentification (RFID) tag that can be used to transmit data between thepersonal care product, e.g. refill 2337, and the display 2345. As knownin the art, an RFID tag comprises an electronic chip that containsencoded information and an antenna that transmits and/or receivesinformation or data (including information stored by the chip) usingradio waves. A reader is used to decode the data transmitted from theRFID tag. The RFID tag may be provided without an internal power supply,and the minute electrical current induced in the antenna by the incomingradio frequency signal from the reader provides just enough power forthe integrated circuit in the tag to power up and transmit a response tothe reader. The RFID tag can be a read only tag or a read/write tag. Thedata stored by a read only tag is pre-programmed, typically by amanufacturer, in non-volatile memory and cannot be changed by a lateruser of the personal care product or system. The data stored by aread/write tag can be later rewritten to the tag during later use,typically by the reader.

The data stored by the RFID tag or other data transmitters/communicatorscan be quite varied, including any personal care information. Some ofthe categories of data includes product identification data (e.g., thebrand name or product name) and product usage or regimen data (e.g.,usage time, such as 1 minute regimen for a rinse, text or graphicalinstructions concerning product usage), one or more rewards, andcomponent or product replacement data (e.g., number of times or lengthof time that a component or product can be used before it should bereplaced). Instructional images, text, or data can be particularlyuseful for children in establishing appropriate brushing regimens.

Data can be directly displayed on the display 2345 or can be used as aninput to the processor for a function or feature of the display 2345.For example, an RFID tag for the refill 2337 could store usage data thatstates the recommended modes of operation. For example, a refill havingpolishing elements may be amenable to the HF/AD mode. As such, when therefill is coupled to the handle, a processor in the handle may restrictthe number of modes available for the refill being utilized. As anotherexample, a refill design for tongue cleaning may be amenable to a tonguecleaning mode but not the TS mode. As such, when the refill is coupledto the handle, the processor. The RFID tag can transmit the usage datato a reader associated with the display 2345.

A data transmitter is a device or component that actively transmits datato a data reader. An RFID tag is an example of a data transmitter. Adata communicator is a device or component that may or may not activelytransmit data but which has data that is capable of being detected.While a data transmitter, such as an RFID tag, is a type of datecommunicator, a data communicator need not necessarily actively transmitdata. Examples of data communicators that contain data that that may bedetected or read by a data reader but which do not actively transmitdata include a bar code (wherein the bar code reader is the datareader), a spotcode, or a hall effect magnet (wherein the hall effectsensor is the data reader). Thus, as will be appreciated, the phrases“data communicators”, “data transmitters” and “data readers” areintended to encompass a wide variety of devices and arrangements for thetransmission, communication, and/or detection of a variety of analog ordigital data, including the mere detection of the presence of a datacommunicator. The phrase “data communication” is intended to encompassall the methods and forms by which data may be transmitted,communicated, and/or detected by a devices of the present invention,including data readers, data transmitters, data communicators, as wellas data communication between a two components such as a display and anelectric toothbrush.

The term “data” is intended to refer to any digital or analoginformation in any form that is transferred or communicated between twodevices or components. Data may include any data actively transmitted bya data transmitter and/or data that is passively detected by a datareader. Data may include ones and zeroes if the data that iscommunicated is digital. In another embodiment, data could be a seriesof digits, such as 12345678, wherein each digit could representinformation about a characteristic of an oral care device (e.g., for amanual toothbrush, the first digit could represent the brushing time inminutes, the second digit could represent the number of months until thebrush should be replaced, the third and fourth digits could represent atype unique reward, etc.). Data may include the arrangement of opticalelements (e.g., a bar code) that represent information. Data may includethe presence or absence of electromagnetic energy (e.g., such as amagnetic field) and the like. The data may be interpreted or decoded bythe processor. For instance, where the data is a series of digits, suchas 12345678, the processor and/or associated memory could comprise a setof instructions that would be able to decode or interpret the data todetermine what information is represented by the data.

The data communication between a data communicator and a data reader canoccur at a variety time before, during, or after an oral care regimenand can be sequential or modulated. For instance, each of a plurality oforal care products having an RFID tag might be moved in proximity of thedisplay 2345 so that the RFID tag can transmit its data to a reader thatis part of the display 2345, the sleeve, or another component of one ofthe personal care systems. The data transmission can occur prior to eachusage of the oral care product or may only need to occur once, such asthe first time the product is used, and the data is thereafter stored bythe reader or a component associated with the reader. A counter can beimplemented that stores the number of times that data is transmittedfrom the RFID tag to the reader for each personal care product.

The display 2345 can provide the user with a plethora of information.For example, in some embodiments, the display 2345 may provide anindication to the user of the modes that are available for a particularrefill. Additionally, the display 2345 may provide a visual indicationof which modes the user has used previously with the current refill orwhich modes the user has used previously with several refills.Additional information that can be provide by the display is discussedin U.S. Pat. Nos. 7,086,111; 7,673,360; and 7,024,717; and in U.S.Patent Application Publication Nos. 2008/0109973A1; 2010/0170052A1; and2010/0281636A1. Additionally, communication between handles, refills,and/or displays is also discussed in U.S. Pat. Nos. 7,086,111;7,673,360; and 7,024,717; and in U.S. Patent Application PublicationNos. 2008/0109973A1; 2010/0170052A1; and 2010/0281636A1.

Test Methods: Oscillation Displacement Angle:

Referring to FIG. 11A, a laser 1110, a lens 1130, light sensors 1120,1121 and a reflective surface 1150, are required. The laser 1110 ismanufactured by Global Laser, HRST-Teilenummer 5200-56-000. The laser1110 is 5 mW with a wavelength of 635 nm in accordance with EN60825, andthe laser 1110 is a class 2M.

The lens 1130 has a 30 mm diameter and is made from PMMA (plexiglass)and has polished surfaces. The lens 1130 is positioned such that thelight emitted from the laser 1110 bisects the thickness of the lens 1130and impinges on a point on the circumference of the lens whichcorresponds to the diameter and not merely a chord of the lens. The lens1130 should focus and split the beam into a line which is generallyperpendicular to the plane of the sheet upon which FIG. 11C is shown.

The light sensors 1120 and 1121 each comprise an array of 56 photodiodeswithout filters which are manufactured by Osram Opto Semiconductors. Thephoto diodes are arranged as shown in FIG. 11B and mounted on a printedcircuit board (PCB). The PCB forms the front-facing surface 1120A and1121A of the sensors 1120 and 1121. The light sensors 1120 and 1121should be positioned equidistant from a horizontal bisecting line 1190of the lens 1130. Additionally, the bisecting line 1190 should beperpendicular to the reflective surface 1150 in the neutral position. Soas positioned, 56 photodiodes are positioned above the the reflectivesurface 1150 and 56 photodiodes below the reflective surface 1150.

A center point of the contact element carrier 1140 should be spaced froma center point of the lens 1130 by a distance 1170 of 44 mm. Similarly,the center point of the contact element carrier 1140 should be spacedfrom front-facing surface 1120A and front-facing surface 1121A of thelight sensors 1120 and 1121 by a distance 1160 of 89 mm. If the contactcarrier element being tested has an elliptical shape, then the centerpoint is where the intersection of the minor axis and the major axisoccur. For other shapes, the geometric center can be utilized as thecenterpoint.

The photodiodes of FIG. 11B should be in signal communication with anevaluator which then sends information to a computer for storage and/oranalysis. The circuit includes a high pass RC filter for filtering outdaylight.

The reflective surface 1150 may be any suitable reflective surface;however, the material selected should reflect as close to 100 percent ofthe light as possible and the material should have sufficient rigiditysuch that during testing, no deflection of the reflective surfaceoccurs. Additionally, the mass of the reflective surface 1150 should bekept small to ensure that that mass of the reflective surface 1150 haslittle if any impact on the performance of the toothbrush being tested.A small sheet of metal, polished, is utilized having a size of 3 mm by11 mm. The reflective surface 1150 is placed at 90 degrees to a longdirection of the refill.

A suitable frame should be constructed to hold a toothbrush andtoothbrush refill to be tested such that during operation, thetoothbrush and refill remain fixed horizontally and vertically. Asshown, a contact element carrier 1140 to be tested should be positionedsuch that the contact elements thereon are positioned as shown, into theplane of the sheet of FIG. 11A. The reflective surface 1150 should beattached tangent to the contact carrier element 1140 and positionedbetween the contact carrier element 1140 and the lens. While thetoothbrush (the contact element carrier 1140) are in an unpowered state,the reflective surface 1150 should be attached normal to a diameter ofthe contact element carrier 1140.

If the contact element carrier 1140 comprises a shape which is otherthan circular, then the refill to be tested should be attached to thehandle to be tested and placed in the frame. The laser 1110 should bepowered on and the toothbrush should remain off Where the laser linefrom the lens 1130 crosses the contact element carrier 1140, thereflecting surface 1150 is attached tangentially. Recall, that thereflecting surface 1150 should be attached such that the bisecting line1190 is perpendicular to the reflecting surface 1150.

As shown in FIG. 11C, a toothbrush to be tested 1100 has a refillattached thereto. The contact element carrier 1140 of the refill has thereflective surface 1150 as described heretofore. Additionally, a plasticplate 1119 can be placed in contact with a contact element field 1118when the oscillation displacement angle is desired under loadedconditions. When the oscillation displacement angle under no load isdesired, then the plate should not be in contact with the contactelement field 1118. For loaded conditions, the linear stepper motor 1115should be advanced in increments of 0.2 mm until the plastic plate 1119applies the desired force on the contact element field 1118 while thetoothbrush is an operating state. The force sensor is manufactured byTesT GmbH and has a model no. K320.20N.

The laser 1110, force sensor, should be calibrated in accordance withthe manufacturer's recommendations prior to testing. Regarding the lightsensors 1120 and 1121 these too should be calibrated. The light sensorscan be calibrated by performing static tests. A device having a mirroris placed in the frame and positioned at a particular angle which can bemeasured physically without the use of the light sensors. The device iskept static and the laser 1110 is powered on. Data is collected andanalyzed to determine if the measured angle corresponds with the anglederived from the light sensor 1120 or 1121 data input. The device shouldbe rotated to test at least three different angles for each of thesensors 1120 and 1121. If discrepancies exist between the measured angleand the derived angle, the evaluation parameters (software) should beadjusted. Repeat calibration steps as required until the measured angleand the derived angle are within five percent of each other.

The computer should be equipped with appropriate software to analyze thevoltages transmitted by the photodiodes. A suitable software for thispurpose is LabView VI.

Place the toothbrush and refill to be tested in the frame where therefill is properly attached to the toothbrush. The refill should beequipped with the reflecting surface 1150 as described heretofore. Fixtoothbrush to the test frame to ensure that the toothbrush does not moverelative to the test frame during testing. Turn on the laser 1110. Turnon the sensor 1120 to make sure that the computer connected to the lightsensors 1120 and 1121 is in a state for recording data. Adjusttoothbrush and/or frame as required such that the light transmitted fromthe lens 1130 achieves the necessary requisites above. Turn on thetoothbrush to the desired mode for which the oscillation displacementangle is to be tested. Record data.

Ensure that a sufficient number of data points are collected andaverages taken in order to validate the oscillation displacement anglemeasurement.

Sound Intensity

All sound measurements were taken in accordance with CEI/IEC 60704-1:1997, entitled “Household and similar electrical applicances—Test codefor the determination of airborne acoustical noise”, which isincorporated herein by reference in its entirety. Any deviations fromthe test method are described below. Specifically, those portions of thetest method referring to hand-held appliances are to be utilized.

All measurements should be done in a semi-anechoic room. A sound meteras provided in the incorporated test methodology is required. Also,additional instrumentation as provided in the incorporated testmethodology. The sound meter should be calibrated in accordance with therecommendations of the manufacturer prior to testing. A test stand asshown in FIG. 12 constructed in accordance with section 6.5.2 of theincorporated test methodology.

A test stand 1500 has a base 1300 placed on an intermediate resilientmeans between the base 1300 and the floor. A rigid vertical support 1310is rigidly connected to the base 1300. A rigid horizontal support 1322is fixed to the rigid vertical support 1310 such that the rigidhorizontal support 1322 does not move during testing. An intermediatebase 1312 is disposed between the base 1300 and the horizontal support1322 and is adjusted such that when the toothbrush is placed on theintermediate base 1312, the brush head has a distance of approximately25 cm from the floor.

The intermediate base 1312 is suspended from the horizontal support 1322by resilient elements 1314 and 1316. The intermediate support 1312comprises a first resilient support 1324 and a second resilient support1326 for supporting a toothbrush 1340 to be tested. The first and secondresilient supports 1324 and 1326, respectively, should be spaced suchthat the toothbrush 1340 remains stationary with respect to theintermediate support 1312 during testing. In an effort to reduce anymovement between the toothbrush 1340 and the intermediate support 1312,resilient element 1350 may be utilized. Additional resilient elementsmay be utilized in order to fix the toothbrush 1340 to the intermediatesupport 1312.

The intermediate support 1312 also has a load support harness 1346 forapplying loads to contact element fields 1344 on refills 1342. The loadsupport harness 1346 should have a smooth bottom surface 1360 and ameans for securing a load 1320 to the load support harness such that theapplied load 1320 does not move with respect to the load support harness1346 during testing.

The toothbrush to be tested should be placed in the test stand 1500 asdescribed above such that the toothbrush does not move relative to theintermediate support 1312 during testing. If an applied load is requiredfor testing, the load support harness 1346 should be placed in contactwith the contact element field prior to beginning the test. Then theappropriate load 1320 should be placed on the load support harness 1346and be secured thereto such that the load 1320 does not move relative tothe load support harness 1346 during testing.

The handles described herein may be any suitable material. Some examplesof suitable material include. Additionally, the handles described hereinmay comprise elastomeric grip features. The elastomeric grip features ofthe handle may be utilized to overmold, at least in part, a portion ofan electrical component or a plurality thereof In such embodiments,these components may be in electrical communication via wiring which cansimilarly be overmolded. The elastomeric grip features may includeportions which are positioned for gripping by the palm of the userand/or portions which are positioned for gripping by the thumb and indexfinger of the user. These elastomeric grip features may be composed ofthe same material or may be different, e.g. color, shape, composition,hardness, the like, and/or combinations thereof.

The refills described herein may be any suitable material. Some examplesof suitable material include. polyoxymethlylene (POM), polyamide (PA),polybutylene terephthalate (PBT), polypropylene (PP), acrylonitrilebutadiene styrene (ABS), the like, and/or combinations thereof. In someembodiments, the refill housing may comprise a first material while thecontact element carrier comprises a second material. The first materialand the second material may be different.

Additionally, as used herein, the term “contact elements” is used torefer to any suitable element which can be inserted into the oralcavity. Some suitable elements include bristle tufts, elastomericmassage elements, elastomeric cleaning elements, massage elements,tongue cleaners, soft tissue cleaners, hard surface cleaners,combinations thereof, and the like. The head may comprise a variety ofcontact elements. For example, the head may comprise bristles, abrasiveelastomeric elements, elastomeric elements in a particular orientationor arrangement, e.g. pivoting fins, prophy cups, or the like. Somesuitable examples of elastomeric cleaning elements and/or massagingelements are described in U.S. Patent Application Publication Nos.2007/0251040; 2004/0154112; 2006/0272112; and in U.S. Pat. Nos.6,553,604; 6,151,745. The cleaning elements may be tapered, notched,crimped, dimpled, or the like. Some suitable examples of these cleaningelements and/or massaging elements are described in U.S. Pat. Nos.6,151,745; 6,058,541; 5,268,005; 5,313,909; 4,802,255; 6,018,840;5,836,769; 5,722,106; 6,475,553; and U.S. Patent Application PublicationNo. 2006/0080794.

The contact elements may be attached to the head in any suitable manner.Conventional methods include stapling, anchor free tufting, andinjection mold tufting. For those contact elements that comprise anelastomer, these elements may be formed integral with one another, e.g.having an integral base portion and extending outward therefrom.

The head may comprise a soft tissue cleanser constructed of any suitablematerial. Some examples of suitable material include elastomericmaterials; polypropylene, polyethylene, etc; the like, and/orcombinations thereof. The soft tissue cleanser may comprise any suitablesoft tissue cleansing elements. Some examples of such elements as wellas configurations of soft tissues cleansers on a toothbrush aredescribed in U.S. Patent Application Nos. 2006/0010628; 2005/0166344;2005/0210612; 2006/0195995; 2008/0189888; 2006/0052806; 2004/0255416;2005/0000049; 2005/0038461; 2004/0134007; 2006/0026784; 20070049956;2008/0244849; 2005/0000043; 2007/140959; and U.S. Pat. Nos. 5,980,542;6,402,768; and 6,102,923.

For those embodiments which include an elastomeric element on a firstside of the head and an elastomeric element on a second side of the head(opposite the first), the elastomeric elements may be integrally formedvia channels or gaps which extend through the material of the head.These channels or gaps can allow elastomeric material to flow throughthe head during an injection molding process such that both theelastomeric elements of the first side and the second side may be formedin one injection molding step.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application, is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1. A personal care device comprising: a handle having an engagementportion; and a personal care attachment comprising an housing attachedto the engagement portion and a contact element carrier, the contactelement carrier being movably coupled to the housing; and a plurality ofcontact elements being arranged on the contact element carrier, whereinthe personal care attachment is driven at a frequency of between about150 Hz to about 175 Hz and has a sound intensity level of less thanabout 75 dB(A).
 2. The personal care device of claim 1, wherein thepersonal care attachment is unloaded.
 3. The personal care device ofclaim 1, wherein the personal care attachment is loaded at 2 N.
 4. Thepersonal care device of claim 1, wherein the personal care devicecomprises a toothbrush and wherein the personal care attachment comprisea refill.
 5. The personal care device of claim 4, wherein the contactelement carrier is rotatably coupled to the housing.
 6. The personalcare device of claim 5, wherein the refill is unloaded.
 7. The personalcare device of claim 5, wherein the refill is loaded at 2 N.
 8. Thepersonal care device of claim 1, wherein the personal care attachmenthas a resonance frequency which is at least 125 percent of the drivingfrequency of the personal care attachment.
 9. A personal care attachmentcomprising: an housing; and a contact element carrier movably mounted tothe housing; a drive member disposed within the housing, the drivemember having a proximal end and a distal end, the proximal end havingan attachment element and the distal end comprising a connection coupledto the contact element carrier, wherein the attachment element comprisea permanent magnet or a magnetisable material.
 10. The personal careattachment of claim 9, wherein the drive member has a cross section thatcan fit within the circumference of a circle having a 6 mm diameter. 11.The personal care attachment of claim 10, wherein the drive member has aY cross section.
 12. The personal care attachment of claim 10, whereinthe drive member has a cruciform cross section.
 13. The personal careattachment of claim 9, wherein the drive member has a resonancefrequency of at least 200 Hz.
 14. The personal care attachment of claim9, wherein the drive member comprises reinforcement fibers.
 15. Thepersonal care attachment of claim 9, wherein the personal careattachment is a refill for a toothbrush.
 16. A personal care attachmentcomprising: an housing; and a contact element carrier movably mounted tothe housing; a drive member disposed within the housing, the drivemember having a proximal end and a distal end, the proximal end havingan attachment element and the distal end comprising a connection coupledto the contact element carrier, wherein the connection is positioned atan angle of less than about 40 degrees with respect to a horizontalplane.
 17. The personal care attachment of claim 16, wherein the drivemember has a cross section that can fit within the circumference of acircle having a 6 mm diameter.
 18. The personal care attachment of claim17, wherein the drive member has a non-circular cross section.
 19. Thepersonal care attachment of claim 16, wherein the drive member has aresonance frequency of at least 200 Hz.
 20. The personal care attachmentof claim 20, wherein the personal care attachment is a refill for atoothbrush.